code: def __init__(self, x1, x2):
      self.x1 = x1
      self.x2 = x2
  
file_path: chainer/chainer/functions/math/minimum.py
imports: from chainer import backend
  from chainer.backends import cuda
  from chainer import function_node
  import chainer.functions
  from chainer import utils
  from chainer.utils import type_check
label_desc: Use image node_id 1 to create a new MinimumGrad object from inherited base classes: function_node with example: obj = MinimumGrad(x1, x2)